Fiber optic end-face transparent protector system and method

ABSTRACT

A protective assembly method using a transparent layer within the fiber interconnect system aids in optical coupling by preventing an air gap from forming between the fiber cores within a connector. A thin transparent film (or with adhesive) is placed over the fiber end-faces at the connector interface, the film having characteristics which allows it to conform to the fiber end and minimize coupling loss between fibers. The film is sized to fit connectors faces and can be temporary, being replaced with each installation. A coating can also applied to the connector surface, providing a similar effect, as well as structurally enhancing the connector surfaces.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of and claims the benefit of U.S.patent application Ser. No. 14/752,986, filed Jun. 28, 2015, whichclaims the benefit of U.S. Provisional Patent Application No.62/019,405, filed Jun. 30, 2014, the contents of which are herebyincorporated by reference in its entirety.

FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT

This disclosure was made with Government support under N68335-11-C-0383awarded by the United States Navy. The government may have certainrights.

FIELD

This present disclosure relates to fiber optic connector interfaces.This disclosure aids in protecting the tip of the fiber, especially theregion that guides light, while allowing light coupling between fibers.This invention can be used to protect fiber optic connector end-facesduring the manufacturing process of cables and also during the generaluse of fiber optic cables.

BACKGROUND

Fiber optic cables are often connected together by aligning and pressingthe ends of two fibers together. The end of the fibers (the ‘end-faces’)are typically polished smooth and flat, or at an angle. The opticalcoupling occurs between the cores of the fibers, which is the centralportion of the fiber that guides the optical energy. The types of fibercan be single-mode-fiber (SMF), with a core that is usually 9 microns indiameter, or multi-mode-fiber (MMF), with a core that is much larger,but typically between 50 to 100 microns in diameter. Efficient opticalcoupling occurs when the cores of the two fibers are aligned and inphysical contact. Ideally, nearly 100% of the light is coupled betweenthe two fibers, but in practice, a loss of up to 0.3 dB may beacceptable.

Imperfections in the fiber end-face polished surface or contaminationtrapped between the cores of the fibers can reduce the efficiency of theoptical coupling. These imperfections can also create an increasedamount of back-reflected light from the connector interface.Imperfections can arise during the handling and use of the fiber.Imperfections can be in the form of scratches or other mechanical damageto the end-face of the fiber. Contamination can result from liquidsources or oils on the fiber end-face. Contamination can also resultfrom particles trapped within the fiber-to-fiber interface. Particlescan originate from the connector itself, for example, from the regionswhere the mechanical alignment mechanisms engage (such as guide holes),or from external sources, such as dust in the environment outside theconnector. A trapped particle can further damage the end-face polish ifthe particle hardness is similar or greater that the glass in the fibercore. A particle can create scratches on the fiber end-face.

The optical coupling efficiency between the two fiber cores is reducedif the fiber cores are not in physical contact and an air gap is createdbetween the cores. An air gap will create a Fresnel reflection ofapproximately 4% at each of the two core-to-air interfaces, a doubleFresnel reflection. If this light is coherent, the interference of thereflections can create additional coupling loss.

Multi-fiber connectors are designed to bring two arrays of fiberend-faces into alignment and create physical contact between the fibercores. The manufacturing process typically polishes the fiber connectorend-face, polishing multiple fibers simultaneously. The polishingprocess typically leaves the tips of the fibers slightly protruding fromthe connector face by 1 to 3 microns. This allows two connectors to mateand have the fiber end-faces make physical contact.

The protrusions of the fiber tips on the connector are not typicallyperfectly uniform. The polishing process may leave a taper or acurvature across the array. Therefore, there is a provision in theconnector to allow the fibers to recess under pressure. A spring can beprovided within the connector to create the pressure. As two fiberconnectors mate, the fibers that have a greater protrusion will comeinto contact first. Under pressure, these two fibers will recede intotheir connector until fibers with less protrusion make physical contact.

A failure in the recess mechanism may make a fiber fail to rebound afterit has been recessed. This failure is called ‘pistoning’. The fiber tiphas been pressed down into the connector, but does not restore to aprotruding state after un-mating of the connector. Pistoning can causefailure of a subsequent mating, as the fiber is not protruding enough tocreate physical contact.

Damage may occur to the fiber end-face during the process ofmanufacturing the fiber optic cable. There may be steps of handling thecable for testing, inspection or installation of the cable into ahigher-level assembly. The manufacturer may ship the cable to a customerthat further handles the cable before final installation into a network.

Fiber optics are finding use in applications that operate in harshenvironments, such as aircraft, helicopters, unmanned vehicles,ship-board, space-craft and missiles. The fiber optic components must beable to operate and survive in an environment with severe shock,vibration, exposure to liquid contaminates, and over wide temperatureranges (such a −55 C to 125 C). These environmental stresses can causethe fiber end-faces, in physical contact within a connector, to becomedamaged or contaminated. Damage may occur when a particle trapped in theoptical interface is moved along the fiber end-face due to vibration,shock or thermal expansion/contraction. This movement may leavescratches on the polish surface of the fiber end-face. An environmentthat exposes the connector to liquid contaminate can compromise opticalcoupling if the liquid enters into an air gap between two fiber cores.

Therefore, there has been a long-standing need for systems and methodsfor providing more precise fiber end coupling. Details of such systemsand methods are provided below.

SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the claimed subject matter. Thissummary is not an extensive overview, and is not intended to identifykey/critical elements or to delineate the scope of the claimed subjectmatter. Its purpose is to present some concepts in a simplified form asa prelude to the more detailed description that is presented later.

In one aspect of the disclosed embodiments, an exposed optical fiber endprotection device is provided for facilitating high optical couplingefficiency between pairs of a plurality of optical fiber ends to bejoined via mating of their respective mechanical optical couplers,comprising: first and second planar tapes, each composed of two stackedtransparent layers, a first layer of the tapes being an adhesive layerand a second layer of the tapes being a support layer for the adhesivelayer and having an index of refraction between approximately 1.1-2.2,and a Rockwell scale E hardness of approximately between 30-150, whereinthe tapes are pre-sized to fit over prospective first and secondmulti-fiber ferrule faces; and pre-formed alignment openings disposed inthe tapes, positioned and sized to align the tapes to the prospectivemulti-fiber ferrule faces and allow passage of prospective ferrulesecuring mechanisms through the alignment openings; wherein the firsttape is adapted to be applied (adhesive-side) to the first prospectivemulti-fiber ferrule face, and the second tape is adapted to be applied(adhesive-side) to the second prospective multi-fiber face, the tapesflexibly conforming around exposed optical finer ends in the ferrulefaces to prevent contamination of the exposed optical fiber ends andreduce Fresnel reflections.

In another aspect of the disclosed embodiments, a method of facilitatinghigh optical coupling efficiency is provided for a mechanical opticalcoupler with another mechanical optical coupler, comprising: forming aplanar tape composed of two stacked transparent layers, a first layer ofthe tape being an adhesive layer and a second layer of the tape being asupport layer for the adhesive layer and having an index of refractionbetween approximately 1.1-2.2, and a Rockwell scale E hardness ofapproximately between 30-150, wherein the tape is pre-sized to fit overa multi-fiber ferrule face; forming pre-formed alignment openings in thetape, positioned and sized to align the tape to the multi-fiber ferruleface and allow passage of ferrule securing mechanisms through thealignment openings; forming a perforate pattern on perimeter of thetape; housing the tape in dispensing cartridge, wherein the cartridgehas one or more exposed faces with the tape therein; aligning themulti-fiber ferrule face to the exposed face of the cartridge to adherethe tape's adhesive layer to the ferrule's face; and retracting themulti-fiber ferrule with the adhered tape from the cartridge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a prior art multi-fiber connector.

FIG. 2 shows an exemplary fiber protector.

FIG. 3 shows an exemplary fiber protector mounted on a multi-fiberconnector.

FIG. 4 shows an exemplary fiber protector with tabs.

FIG. 5 shows an exemplary fiber protector with tabs mounted on amulti-fiber connector.

FIG. 6 shows an exemplary fiber optic coupling over a gap.

FIG. 7 shows a plot of an exemplary fiber optic coupling versus thewidth of the gap.

FIG. 8 shows an exemplary fiber protector with an adhesive layer.

FIG. 9 shows a side view of an exemplary fiber protector on amulti-fiber connector.

FIG. 10 shows two fiber connectors mated with an exemplary fiberprotector in-between.

FIG. 11 shows two fiber connectors mated with two an exemplary fiberprotectors in-between.

FIG. 12 shows an exemplary multi-fiber connector with a coating thatprotects the fiber.

FIG. 13 shows two exemplary fiber connectors mated that have a coatedfiber protector.

FIG. 14 shows an exemplary cartridge for applying film.

FIG. 15 shows an exemplary process using a film-based fiber protector.

FIG. 16 shows an exemplary manufacturing flow for permanent coating.

DETAILED DESCRIPTION

The exemplary fiber optic interface system, and the assembly method of atransparent layer within the interconnect system, are described in thisapplication. This system creates a fiber optic interface system thatplaces a thin transparent film over the fiber end-faces at the connectorinterface. This system can use a temporary film, designed to be removedor replaced if necessary, or a permanent layer, designed to remain onthe fiber end-face through the life of the fiber cable. The film is thinand transparent creating minimal additional coupling loss between tofibers. The additional coupling loss can be small enough to allow fiberoptic cable testing and general use with the layer in place.

The system aids in optical coupling by preventing an air gap fromforming between the fiber cores within a connector. The system may alsoprevent damage to the fiber end-faces during cable manufacturing andgeneral use. The system may prevent foreign objects or liquids frombecoming trapped between the fiber cores within a connector.

The temporary film is applied in a manner that covers the end-faces offibers at a connector interface. The film supplies compliance to allowthe fiber end-faces to embed themselves into the film, making physicalcontact between the fiber core and the film. The film can be made up ofmultiple layers, such as an adhesive layer and a structural layer. Theadhesive layer can allow the film to be applied and removed from thefiber end-faces. Ideally, the adhesive layer leaves no residues on thefiber end-faces after removal.

The permanent film can be applied one time and remains on the fibercable throughout the lifetime use. The permanent film may includeadditional functionality of coating the fiber connector interface andpreventing pieces of the fiber connector from breaking off during matingof the connector.

A temporary film may be applied using a cartridge containing multiplefilms. The cartridge can have method of aligning the fiber connectorend-face to the film during application. The cartridge can providemechanical support of the film during application. The cartridge mayoperate in a tool that provides a means to apply the film onto the fiberend-face. The tool may have a feature to apply a film to a connector,and then advance the cartridge to another region on the cartridge forapplication on another connector.

The permanent film may be applied with a coating process. The coatingprocess may apply the film to the region of the fiber end-faces, theentire end-face or a region that includes some or all of the entireconnector.

The exemplary system(s) and method(s) has application in the generalfield of fiber optic cables. It can be used during the manufacturingprocess to protect the fiber end-face, without sacrificing the abilityto measure the optical coupling properties of the cable. It can be usedto protect fiber cables that are found in higher-level assemblies (suchas modules, or box-level solutions) during the manufacturing and testprocess of the assembly. The exemplary system(s) and method(s) can aidthe connector performance in harsh environment applications; and canrelax the polishing specifications normally required to create physicalcontact between fiber cores.

FIG. 1 is an illustration of a prior art multi-fiber connector 110 thatis made up of a ferrule 115 that holds fibers 130 aligned to each otherand to an alignment mechanism 120. There are many types of alignmentmechanisms 120, including, but not exclusively, guide pin and guideholes, features that are processed monolithically into the ferrule 115,or features that align the outer body of the ferrule 115, such as asleeve. The alignment mechanism 120 provides a means to align two of themulti-fiber connectors 110 together during the mating of two sets of thefibers 130, so that light couples between the fibers. The fibers 130 canbe polished or cleaved so that the ends of the fibers are roughly flator at an angle. The fibers 130 and face of the ferrule 115 can bepolished together in a single processing step. The fibers 130 canprotrude slightly from the ferrule 115 to allow for physical contactwith another set of fibers (not shown) in a mating ferrule. A typicalfiber protrusion is 1 to 3 microns. The fibers 130 can be mounted intothe ferrule 110 using an adhesive that provides compliance to allow thefibers 130 to recess toward the ferrule 110 when pressure is applied tothe ends of the fibers 130 during connector mating. It should beapparent that the exposed fiber 103 ends, renders them susceptible tocontamination (from debris, dust, etc.) or even damage. To date, thereis no known protection scheme other than the installer perhaps placing arag over the multi-fiber connector 110 whilst preparing the matingconnector. The following Figures show various improvements to the priorart.

FIG. 2 shows one embodiment of an exemplary fiber protector 1 sade witha transparent film 160. The film can have clearance 170 regions toprevent mechanical interference with alignment mechanisms 120, ifpresent, or other features within the connector. The clearance 170features can aid in alignment of the film to the ferrule 110 during theapplication process. The clearance 170 regions can have aclearance-to-edge slot 172 or other feature (micro slots aroundclearance 170, etc.) that eases the installation or removal of the fiberprotector 150. The film 160 is thin and in some embodiments isapproximately less than 50 microns. The film should be soft enough toconform around the fiber end-face. In commercial embodiments, a Rockwellscale E hardness of the film in the range of approximately 30 and 150was found to be effective. Of course, other values may be foundeffective, depending on the implementation. A non-exhaustive list offilm materials that may be suitable are polyimide, polyethylene,polyurethane, and silicone. The fiber protector 150 can be manufacturedby cutting or stamping a pattern into a film. A laser could be used forcutting the film, as well as other suitable manufacturing methods. Thefiber protector 150 can be applied to a fiber connector 202 having 1 ormore fibers.

FIG. 3 shows an exemplary fiber protector 150 mounted on a prior artmulti-fiber connector 202, creating a protected connector 200. The fiberprotector 150 covers the fiber(s) to create protected fiber(s) 205. Thefiber protector 150 can have a clearance around the alignment mechanism204 on the fiber connector 202.

FIG. 4 shows an exemplary fiber protector 250 with extending tabs. Inthis embodiment, tabs 260 are provided onto the fiber protector 250 toease in the removal of the film 160. The tabs 260 can be placed in anarea convenient to grasp that does not interfere with the overalloperation of the connector and be of any suitable shape or size.

FIG. 5 shows a multi-fiber connector 202 with a mounted fiber protectorwith tabs 250, creating a protected connector 300. In this embodiment,the tabs 260 are on two sides of the fiber protector 250 and protrudeabove and below the fiber connector 202. It should be understood thatwhile two tabs 260 are shown, less or more tabs 260 may be used,according to design preference.

The transparent fiber protector 250 creates a small gap between fiberswithin a fiber connection. FIG. 6 shows is a closeup side illustrationshowing the detail of fiber coupling over this gap from a transmit fiberto a receive fiber. The transmit fiber is made up of a transmit fibercore 336, which contains the light, and a transmit fiber cladding 332.Similarly, the receive fiber has a receive fiber core 352 and receivefiber cladding 356. The material for both the core and the cladding isglass having a different reflective index for the two regions. Theobjective is to couple optical energy efficiently (typically >90%) fromthe transmit core to the receive core. The light path 328 within thetransmit core 336 will experience a transmit reflection 344 at the endof the transmit fiber, and a receive reflection 348 at the start of thereceive fiber. These are Fresnel reflections, caused by the differencein the index of refraction of materials. Only when the gap 360 isreduced to zero thickness (d=0) are the reflections nearly eliminated,since the fiber core materials have a nearly identical index ofreflections (i.e., the difference in index would result from fibermanufacturing non-uniformity). If the gap 360 contained air, themagnitude of the Fresnel reflections would be approximately 4%,resulting in 0.36 dB of optical signal loss from the combined transmitreflection 344 and receive reflection 348. If the gap 360 is filled witha transparent film 340 that nearly matches the fiber core index ofrefraction, the Fresnel reflections can be substantially reduced.Therefore, in commercial embodiments, a suitable index of refraction forthe film was set to 1.5, the typical index of the fiber core. However,any film with an index of refraction between 1.1 and 2.2 will produceless reflection than an air gap.

The film 340 can also create loss due to light scattering andabsorption. However, in a commercial embodiment, the amount ofscattering and absorption is negligible (<1%).

FIG. 7 is a plot showing measured results of fiber optic couplingbetween two fibers versus a film thickness. The type of fiber was a 50micron graded index multi-mode fiber. The film was a polyethylene. Thecoupling was measured for gap 360 thickness d at steps of 5 microns withthe gap filled with the film. A coherent laser source was used for thismeasurement, which shows up as some variations at gap thicknesses of d=5microns and d=10 microns. If an application had an acceptable lossbudget of −0.2 dB, a film thickness of roughly 25 microns would beexpected to be acceptable with this film.

A transparent adhesive layer added to the transparent film can aidsecuring the fiber protector in place on the connector. FIG. 8 is across-sectional illustration of an exemplary fiber protector 390 with atransparent adhesive layer 394 added. The adhesive layer 394 should bethin, for example, less than 25 microns. In the process of making thefiber protector 390, clearance 170 areas can be formed in the film 392.Silicone or acrylate adhesives are possible candidates for thetransparent adhesive 394. Of course, other suitable adhesives may beused, according to design preference. The adhesive, in some embodiments,allows the fiber protector 390 to be removed without leaving residue onthe fiber connector 202. For outdoor environment applications, the filmand adhesive should be chosen to survive in temperature extremes and inthe presence of moisture.

The transparent film 392 can also be coated to improve the surfacequalities for optical (i.e., anti-reflection or absorption coatings) andmechanical reasons. For example, the mechanical qualities can beimproved with a diamond coating to provide resistance to scratches.

FIG. 9 shows a top side, cut-away view 400 of a single fiber protector150 on a multi-fiber connector 100. The multi-fiber connector 110 hasalignment mechanisms 120, such as a guide hole or guide pin, and fiberends 410 that protrude. Due to manufacturing variations, the fiber ends410 may not protrude uniformly across an array of fibers. The fiber ends410 are in contact with the fiber protector 150 is a manner that reducesthe Fresnel reflections at this interface. The top surface of the fiberprotector 150 can be substantially flat.

FIG. 10 shows a top side, cut-away view of a fiber connector 450 firstside 401 mated to a fiber connector second side 402 so that one or morefibers are brought into alignment for the purpose of optical coupling.In this embodiment, a single fiber protector 150 is shown. An alignmenthole first side 461 is aligned to alignment hole second side 462 with analignment pin 460. This shows one method of achieving alignment, howeverother methods are possible. A fiber protector 150 is applied to fiberconnector first side 401. The fiber ends first side 411 and fiber endssecond side 412 are in physical contact with the fiber protector 150.Light is coupled from the fiber ends first side 411 to the fiber endssecond side 412.

FIG. 11 shows a top side, cut-away view of a fiber connector 500 firstside 401 mated to a fiber connector second side 402 so that one or morefibers are brought into alignment for the purpose of optical coupling.In this embodiment, two fiber protectors are utilized between therespective connector fibers. An alignment hole first side 461 is alignedto alignment hole second side 462 with an alignment pin 460. This showsone method of achieving alignment, however other methods are possible. Afirst fiber protector first side 505 is applied to fiber connector firstside 401. The fiber ends first side 411 are in physical contact with thefiber protector first side 505. A fiber protector second side 510 isapplied to fiber connector second side 402. The fiber ends first side412 are in physical contact with the fiber protector second side 510.The fiber protector first side 505 is in physical contact with the fiberprotector second side 510. Light is coupled from the fiber ends firstside 411 to the fiber ends second side 412. Evident is the conforming ofthe fiber protector sides to the ends of the respective fibers, thusensuring a non-air gap.

FIG. 12 shows a top side, cut-away view of multi-fiber connector 600with a coating that permanently protects the fiber. The fiber connector610 has one or more fibers and may have an alignment mechanism, such asan alignment hole 620 or guide pin. The fiber ends 410 can be protrudingfrom the fiber connector 610. A fiber protection coating 615 is appliedpermanently to the fiber connector 610. The fiber protection coating 615covers the fiber ends 410. The fiber protection coating 615 may beapplied with vapor deposited process, such as parylene or organiccoatings. In commercial embodiments, a process that 1 micron precisionof the coating thickness was used to provide consistent results. In oneembodiment, the coating is applied to the entire fiber connector 610,including inside the alignment holes 610. In this embodiment, the innerdiameter of the alignment hole 620 is reduced by the coating. To retainprecision, the coating thickness inside the alignment hole 620 should bewell controlled. A coating process with 1 micron thickness precision isadequate for most fiber-to-fiber alignment applications.

The process of mating guide pins into alignment holes 620 can causedamage 618 in the region around the alignment holes 620. Pieces of thefiber connector 610 can break away in these regions. The fiber protectorcoating 615 can reduce this damage 610 and also retain the pieces thatwould otherwise break away.

FIG. 13 shows a top side, cut-away view of two fiber connectors 650mated that have a permanent coated fiber protector. The fiber connectorfirst side 401 has a fiber protector coating first side 611 that is apermanent coating over the fiber ends first side 411. The fiberprotector coating first side 611 may optionally coat the entire fiberconnector first side 401, including the inside of the alignment holefirst side 621. A fiber connector second side 402 has a permanent fibercoating second side 612 that protects the fiber ends second side 412. Analignment pin 630 can provide an alignment mechanism.

The fiber ends first side 411 are aligned to fiber ends second side 412so that light couples through the protector coating between the fibers.The fiber protector coating first side 611 is in physical contact withthe fiber ends first side 411 and the fiber protector coating secondside 612. The fiber ends second side 412 are in physical contact withthe fiber protector coating second side 612.

The suitable index of refraction for the coating is 1.5, the typicalindex of the fiber core used in the industry. However, any coating withan index of refraction between 1.1 and 2.2 produced less reflection thanan air gap. For outdoor environment applications, the coating should bechosen to survive in temperature extremes and in the presence ofmoisture.

FIG. 14 is an illustration 800 of a method of applying the exemplaryfilm with a cartridge. A mechanical support 805 provides the mechanismof holding the film 820 and alignment of the fiber connector(s) 830 tothe film 820. The film 820 is applied to the mechanical support 805 andpatterned to match the fiber connector face 835. This pattern caninclude clearance 170 for alignment mechanisms, pin slots (not shown),and a perforate pattern 802 to allow the fiber protector 150 to releasefrom the film 820. The fiber connector 830 is pressed into the ferrulealignment mechanism 810 (which may be a hole in the support that matchesthe outer dimensions of the fiber connector 830). The adhesive side ofthe film 825 is mated to the fiber connector face 835, to create a fiberconnector aligned that is face mated 840 into film 820. The cartridgecan be a standalone element, or it can be contained into a higher leveltool that provides indexing of the cartridge.

FIG. 15 is a process flow 900 illustrating an example of filmprotection. First, the ferrule has final processing the fiber end-face910. At this point the fiber ends are in their final state, such aspolished or cleaved. These fibers are then inspected and tested forquality 915 (for example, optical inspection with an interferometer andoptical coupling tests). If the quality is not acceptable 920, theferrule may be re-processed. If acceptable 920, the film is applied 925.Then the ferrule is inspected and tested 930. If the ferrule does notpass the test 935, the film is re-applied 925. If the ferrule passes thetest 935, it is optionally assembled into a higher level cable 940. Thecable is shipped to a customer 945. The customer can inspect and testthe cable 950, insert the cable in a module 955 and test the module inenvironmental conditions 960. After testing the film can be optionallyremoved 965 or left in place for final test 970 and system integration.

FIG. 16 shows a manufacturing flow 1000 for a cable created with thecoating. The fibers are processed into the ferrule 1010. This stepincludes inserting the fibers into the ferrule, and processing the fiberends (polishing or cleaving). The next step is to inspect and testquality 1015 of the fiber connector. If the quality is not acceptable1020, the ferrule is re-processed. If the quality is acceptable 1020,the next step is to apply the protector coating to the ferrule 1025,then inspect and test with the coating (1030). The ferrule may be thenassembled into a higher-level cable assembly 1040 and then final test1045.

In view of the above, it should be appreciated by one skilled in the artthat the functional blocks, methods, devices and systems described inthe present disclosure may be integrated or divided into differentcombinations of systems, devices, and functional blocks, as would beknown to those skilled in the art.

For example, while the process steps, algorithms or the like may bedescribed in a sequential order, such processes may be configured towork in different orders. In other words, any sequence or order of stepsthat may be explicitly described does not necessarily indicate arequirement that the steps be performed in that order. The steps ofprocesses described herein may be performed in any order practical.Further, some steps may be performed simultaneously despite beingdescribed or implied as occurring non-simultaneously (e.g., because onestep is described after the other step). Moreover, the illustration of aprocess by its depiction in a drawing does not imply that theillustrated process is exclusive of other variations and modificationsthereto, does not imply that the illustrated process or any of its stepsare necessary to the invention, and does not imply that the illustratedprocess is preferred.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. An exposed optical fiber end protection devicefor facilitating high optical coupling efficiency between pairs of aplurality of optical fiber ends to be joined via mating of theirrespective mechanical optical couplers, comprising: first and secondplanar tapes, each composed of two stacked transparent layers, a firstlayer of the tapes being an adhesive layer and a second layer of thetapes being a support layer for the adhesive layer and having an indexof refraction between approximately 1.1-2.2, and a Rockwell scale Ehardness of approximately between 30-150, wherein the tapes arepre-sized to fit over prospective first and second multi-fiber ferrulefaces; and pre-formed alignment openings disposed in the tapes,positioned and sized to align the tapes to the prospective multi-fiberferrule faces and allow passage of prospective ferrule securingmechanisms through the alignment openings; wherein the first tape isadapted to be applied (adhesive-side) to the first prospectivemulti-fiber ferrule face, and the second tape is adapted to be applied(adhesive-side) to the second prospective multi-fiber face, the tapesflexibly conforming around exposed optical finer ends in the ferrulefaces to prevent contamination of the exposed optical fiber ends andreduce Fresnel reflections.
 2. The protection device of claim 1, whereinthe tapes are removable.
 3. The protection device of claim 1, whereinthe tapes are of a uniform thickness.
 4. The protection device of claim1, further comprising substantially smaller openings disposed in atleast one of the tapes, adjacent to the alignment openings, adapted tocause the alignment openings of the tape to be more easily affixed orremoved from or to the ferrules' securing mechanism, than without thesmaller openings,
 5. The protection device of claim 1, wherein thesupporting layer is a polyimide, polyethylene, polyurethane, orsilicone.
 6. The protection device of claim 1, further comprisinggripping tabs protruding vertically from the tapes' boundaries.
 7. Theprotection device of claim 1, wherein a tape's index of refraction isapproximately 1.5.
 8. The protection device of claim 1, wherein thetape's thickness is approximately between 50-25 microns.
 9. Theprotection device of claim 1, wherein the tapes are manufactured bymechanical cutting, laser cutting or a pattern stamp.
 10. The protectiondevice of claim 1, wherein the adhesive in the adhesive layer issilicone or acrylate.
 11. The protection device of claim 1, furthercomprising a first and second mechanical optical coupler's ferrules. 12.The protection device of claim 1, further comprising a tape dispensingcartridge, wherein the tapes are patterned to match a face of one ormore mechanical optical coupler's ferrules.
 13. The protection device ofclaim 12, further comprising a perforate pattern on the tapes.
 14. Theprotection device of claim 13, wherein the tapes are sized for adifferent mechanical optical coupler's ferrule face.
 15. A method offacilitating high optical coupling efficiency for a mechanical opticalcoupler with another mechanical optical coupler, comprising: forming aplanar tape composed of two stacked transparent layers, a first layer ofthe tape being an adhesive layer and a second layer of the tape being asupport layer for the adhesive layer and having an index of refractionbetween approximately 1.1-2.2, and a Rockwell scale E hardness ofapproximately between 30-150, wherein the tape is pre-sized to fit overa multi-fiber ferrule face; forming pre-formed alignment openings in thetape, positioned and sized to align the tape to the multi-fiber ferruleface and allow passage of ferrule securing mechanisms through thealignment openings; forming a perforate pattern on perimeter of thetape; housing the tape in dispensing cartridge, wherein the cartridgehas one or more exposed faces with the tape therein; aligning themulti-fiber ferrule face to the exposed face of the cartridge to adherethe tape's adhesive layer to the ferrule's face; and retracting themulti-fiber ferrule with the adhered tape from the cartridge.
 16. Themethod of claim 14, further comprising coupling, via the ferrulesecuring mechanisms, the taped ferrule face to another multi-fiberferrule.